Methods of forming material over a substrate and methods of forming capacitors

ABSTRACT

A method of forming a material over a substrate includes performing at least one iteration of the following temporally separated ALD-type sequence. First, an outermost surface of a substrate is contacted with a first precursor to chemisorb a first species onto the outermost surface from the first precursor. Second, the outermost surface is contacted with a second precursor to chemisorb a second species different from the first species onto the outermost surface from the second precursor. The first and second precursors include ligands and different central atoms. At least one of the first and second precursors includes at least two different composition ligands. The two different composition ligands are polyatomic or a lone halogen. Third, the chemisorbed first species and the chemisorbed second species are contacted with a reactant which reacts with the first species and with the second species to form a reaction product new outermost surface of the substrate.

RELATED PATENT DATA

This patent resulted from a continuation application of U.S. patentapplication Ser. No. 12/720,305, filed Mar. 9, 2010 (now U.S. Pat. No.8,501,268), entitled “Methods Of Forming Material Over A Substrate AndMethods Of Forming Capacitors”, naming Zhe Song and Chris M. Carlson asinventors, the disclosure of which is incorporated by reference.

TECHNICAL FIELD

Embodiments disclosed herein pertain to methods of forming material overa substrate and to methods of forming capacitors.

BACKGROUND

Various technologies have been developed for applying thin films oversubstrates, and particularly for applying thin films during fabricationof devices of integrated circuitry. Such technologies include chemicalvapor deposition (CVD) and atomic layer deposition (ALD). Both ALD andCVD use volatile precursor materials to form a desired material onto asubstrate. CVD and ALD differ from one another, however, in that CVDincludes reaction of precursors in vapor or plasma phase over asubstrate which then forms a deposit onto the substrate. ALD, on theother hand, comprises chemisorption of a precursor component onto asubstrate followed by a reaction involving the chemisorbed component toform a desired deposit onto the substrate.

ALD has been used to deposit dielectrics for capacitors, for exampleoxides such as aluminum oxide, hafnium oxide, and zirconium oxide. Insome instances, such oxides are deposited to include multiple differentmetals and/or metalloids, for example Hf_(x)Al_(y)O_(z),Zr_(x)Al_(y)O_(z), and Zr_(x)Si_(y)O_(z). The majority metal componentof such materials often provides the desired predominant property of thefilm, for example Hf or Zr for high dielectric constant. The minoritymetal component may be provided to offset an undesired characteristiccontributed by the majority metal component, for example providing Al orSi to reduce leakage current. Accordingly, it is desirable to be able tocarefully control the respective quantity of each respectivemetal/metalloid in a multiple metal/metalloid dielectric.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagrammatic sectional view of a substrate in process inaccordance with an embodiment of the invention.

FIG. 2 is a view of the FIG. 1 substrate at a processing step subsequentto that of FIG. 1.

FIG. 3 is a view of the FIG. 2 substrate at a processing step subsequentto that of FIG. 2.

FIG. 4 is a view of the FIG. 3 substrate at a processing step subsequentto that of FIG. 3.

FIG. 5 is a diagrammatic sectional view of a substrate in process inaccordance with an embodiment of the invention.

FIG. 6 is a view of the FIG. 5 substrate at a processing step subsequentto that of FIG. 5.

FIG. 7 is a view of the FIG. 6 substrate at a processing step subsequentto that of FIG. 6.

FIG. 8 is a diagrammatic sectional view of a substrate in process inaccordance with an embodiment of the invention.

FIG. 9 is a view of the FIG. 8 substrate at a processing step subsequentto that of FIG. 8.

FIG. 10 is a view of the FIG. 9 substrate at a processing stepsubsequent to that of FIG. 9.

FIG. 11 is a diagrammatic sectional view of a substrate processed inaccordance with an embodiment of the invention.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

First embodiments of methods of forming a material over a substrate 10are described with reference to FIGS. 1-4. Substrate 10 may comprise asemiconductor or other substrate, and regardless may be homogenous ornon-homogenous comprising multiple different composition regions and/orlayers. In the context of this document, the term “semiconductorsubstrate” or “semiconductive substrate” is defined to mean anyconstruction comprising semiconductive material, including, but notlimited to, bulk semiconductive materials such as a semiconductive wafer(either alone or in assemblies comprising other materials thereon), andsemiconductive material layers (either alone or in assemblies comprisingother materials). The term “substrate” refers to any supportingstructure, including, but not limited to, the semiconductive substratesdescribed above. Substrate 10 comprises substrate material 12 that hassome outermost surface 14. Substrate material 12 may or may not behomogenous, and outermost surface 14 may or may not be planar. Forexample, outermost surface 14 may undulate and/or comprise differentraised and/or recessed features (not shown).

An embodiment of a method of forming a material over a substratecomprises performing at least one iteration of the following temporallyseparated ALD-type sequence involving at least the following first,second, and third stated acts upon the substrate. Additional processingmay occur before, intermediate, or after the stated acts, with referenceto first, second, and third throughout this document only requiringtemporal order relative to one another in an iteration. Further,“ALD-type” refers to technologies that are either true ALD processes orthat are more similar to ALD processes than to other depositionprocesses, as is described in U.S. Patent Application Publication No.2006/0251813 which is fully incorporated by reference as if included inits entirety herein.

In a first part of an iteration of one embodiment, and referring to FIG.2, outermost surface 14 of substrate 10 has been contacted with a firstprecursor to chemisorb a first species onto outermost surface 14 fromthe first precursor. The first precursor comprises a central atom and atleast two different composition ligands which are either polyatomic or alone halogen. Additional composition ligands may be included as long asat least two are at least one of polyatomic or a lone halogen. In oneembodiment, at least one of the different composition ligands ispolyatomic, and in one embodiment at least one of the differentcomposition ligands is a lone halogen. In one embodiment, at least twoof the different composition ligands are different lone halogens. In oneembodiment, at least two of the different composition ligands arepolyatomic, and in one embodiment none of the different compositions isa lone halogen. In one embodiment, all of the ligands of the firstprecursor are of only two different compositions, and in one embodimentthe ligands of the first precursor are of more than two differentcompositions.

The first species may or may not be equally spaced relative one anotheron the outermost surface to which such chemisorb. Further, the firstspecies may or may not saturate such outermost surface taking intoconsideration the available outermost surface bonding sites incombination with the steric effect/hindrance of the ligand(s) remainingbonded to the central atoms. Ideally, saturation or near-saturation ofthe outermost surface by the first species is achieved.

FIG. 2 depicts an example first precursor M₁A_(j)D_(m), where M₁ is acentral atom and A and D are two different composition ligands which areeither individually polyatomic or a lone halogen. The central atom mayor may not be a “metal” element as defined in U.S. Patent ApplicationPublication No. 2006/0251813. The suffixes “j” and “m” are numbersgreater than zero, may be the same or different, and may or may not beintegers. The central atom of the first precursor may be monovalent,bivalent, trivalent, or tetravalent, with “j” and “m” totaling 1, 2, 3,or 4, respectively. The central atom of the first precursor may behigher than tetravalent, with “j” and “m” thereby totaling more than 4.The first precursor may or may not be stoichiometric. FIG. 2 depicts achemisorbed first species M₁D_(u), where the suffix “u” is a numberequal to or less than “m”, is greater than zero, and may or may not bean integer. Accordingly by way of example only, FIG. 2 depicts anembodiment wherein the first precursor includes only two differentcomposition ligands and the first species includes only one of the twodifferent composition ligands. Alternately, some A ligands may remain aspart of the first species.

In one embodiment, the first precursor has greater quantity of one ofthe two different composition ligands than the other of the twodifferent composition ligands, and in one embodiment in such instancethe first species may be void of the one ligand. In one embodiment, oneof the different composition ligands in the first precursor is largerthan all remaining ligands in the first precursor of differentcomposition from the one ligand, and the first species comprises more ofthe one ligand than any of the remaining ligands. In such instance, thefirst species may be void of the remaining ligands or include one ormore of the remaining ligands. Where at least one of the differentcomposition ligands is polyatomic, such by way of example may be any ofalkyl, allyl, alkoxy, amino, amido, imido, cyclic, aromatic, alicyclic,heterocyclic, or polycyclic.

Specific polyatomic ligands include the following, and theirderivatives: methyl, ethyl, isopropyl, n-butyl, isobutyl, tert-butyl,neopentyl, cyclopentadienyl, methoxy, ethoxy, isopropoxy, isobutoxy,tert-butoxy, 1-methoxy, 2-methyl, 2-propoxy, dimethylaminoethoxy,acetylacetonato; 2,2,6,6-tetramethyl, 3,5-heptanedionato,1,1,1,5,5-hexafluoroacetylacetonato, octane-2,4-dionato,1-(2-methoxyethoxy)-2,2,6,6-tetramethyl, 3,5-heptanedionato,2-amino-pent-2, en-4-onato, acetox; dimethylamido, ethylmethylamido,diethylamido, bis(trimethyl-silyl)amido; tert-butylimido,N,N′-diisopropyl-acetamidinato, N,N′-ditertbutylacetamidinato,1,10-phenanthroline, dimethylglyoximato, diethyldithio-carbamato,aryloxy, amidinate, β-diketonate, ketoiminate, amine, silanoate;carboxylate, ether, furan, pyridine, pyrole, pyrrolidine, glyme,nitrile, to name a few by way of example only.

In a second part of the iteration, the outermost surface is contactedwith a second precursor to chemisorb a second species onto the outermostsurface. The second species is different from the first species. Thesecond precursor comprises a central atom and ligands, with the centralatoms of the first and second precursors being different. The secondprecursor may or may not comprise at least two different compositionligands and, if so, one or more of the different composition ligands mayor may not be the same as the at least two different composition ligandsof the first precursor. Regardless, in one embodiment, one of theligands of the first precursor may be larger than each ligand in thesecond precursor.

FIG. 3 depicts an example embodiment wherein the second precursor isrepresented as M₂E_(q), wherein all of the ligands E of the secondprecursor are of the same composition. The central atom M₂ may or maynot be a “metal” element as defined in U.S. Patent ApplicationPublication No. 2006/0251813. The suffix “q” is some number greater thanzero, and may or may not be an integer. The central atom of the secondprecursor may be of any valence, and the second precursor may or may notbe stoichiometric. The second species chemisorbed onto outermost surface14 is represented as M₂E_(t), where “t” is some number less than “q”, isgreater than zero, and may or may not be an integer. Example ligands Einclude any of those described above with respect to the firstprecursor. However ideally, the compositions of D and E are different.The combination of the chemisorbed first and second species of FIG. 3may or may not result in a saturated or near-saturated monolayer.Regardless, the chemisorbed second species may or may not be largelyequally spaced relative to one another and/or relative to thechemisorbed first species. Regardless, the quantity of the chemisorbedsecond species may be greater or less than the chemisorbed firstspecies. Ideally, such will be less than the chemisorbed first species.For simplicity, FIG. 3 shows a ratio of first species to second speciesof 3:1, with uniform ordering and equal spacing of the respectivelyadhered species. Such exact ordering and spacing would be unlikely inpractice.

In a third part of the iteration, and referring to FIG. 4, thechemisorbed first species (not shown) and the chemisorbed second species(not shown) are contacted with a reactant R which reacts with the firstspecies and with the second species to form a reaction product 15 and anew outermost surface 16 of substrate 10. Composition of reactionproduct 15 is exemplified by a combination of M₁R* and M₂R*, where R* issome component of reactant R. Alternately considered, the reactionproduct may be collectively considered or represented as M₁ _(x) M₂ _(y)R*_(z). The reactant may, by ways of example only, comprise oxygen,nitrogen, or silicon to convert the chemisorbed material of FIG. 3 to adesired composition such as, for example, an oxide, a nitride, or asilicide, respectively.

Suitable pump and/or purge steps may occur before or after any of theabove first, second, and third parts.

The above iteration may be repeated one or more times whereby newoutermost reaction product surfaces are created to ultimately achieve asuitable desired thickness of material over substrate material 12.Additionally and/or alternately, another precursor having the same ordifferent central atom with respect to one of the first and secondprecursors could be used immediately before or after exposure to thereactant. Regardless, other processing may occur before or after any ofthe first, second, and third parts of the above iteration. Further, thereaction product of different iterations may be different depending onprecursors which are used.

The invention may enable, although not necessarily require, takingadvantage of the steric effect/hindrance of different compositionligands in the first precursor to better control desired quantity of M₁and M₂ in the example deposited M₁ _(x) M₂ _(y) R*_(z). material. Forexample, where the first species retains a large ligand from the firstprecursor in comparison to size of each ligand in the second precursor,a lower quantity of the first species may be chemisorbed onto theoutermost substrate surface providing more bonding sites on theoutermost surface for the second species. In other words, the presenceof the larger ligands of the first species, due to steric effect orsteric hindrance, reduces the number of available bonding sites for thefirst species. This provides more bonding sites when the secondprecursor contacts the same outermost surface, particularly where theligands of the second precursor are all smaller than the individualligand(s) remaining in the first species. Further, the first species maymore tenaciously adhere to the outermost surface where the first speciesonly contains one or more large ligands whereby the first species isless likely to be displaced from the outermost surface by the act ofexposing the substrate to the second precursor. In one ideal embodiment,the first species retains only a single polyatomic ligand from the firstprecursor, with such single ligand being larger than all individualligands of the second precursor. Further ideally in such embodiment, thesingle ligand is cyclic and/or all individual ligands of the secondprecursor are smaller than the single polyatomic ligand of the firstprecursor and/or all ligands of the second precursor are of the samecomposition. Ideal control and results have been achieved where thefirst species retains only a single cyclic ligand, and all ligands ofthe second precursor are of the same composition which is not cyclic andis smaller than the single cyclic ligand of the first species.

Regardless, in one embodiment where one of the ligands in the firstprecursor is larger than each ligand in the second precursor and thefirst species comprises the one ligand, steric hindrance is used informing the first species to reduce saturation of the central atom ofthe first precursor chemisorbed to the outermost surface than wouldotherwise occur under identical process conditions using a differentfirst precursor not having such one ligand. Subsequently, the forming ofthe second species from the second precursor increases quantity of thecentral atom of the second precursor chemisorbed to the outermostsurface than would otherwise occur when forming the first species undersaid identical process conditions using a different first precursor nothaving said one ligand.

The above embodiments of FIGS. 1-4 used a first precursor that comprisedat least two different composition ligands that are at least one ofpolyatomic or a lone halogen independent of whether the second precursorhad multiple different composition ligands. An alternate embodiment isdescribed with reference to FIGS. 5-7 wherein the second precursorrequires at least two different composition ligands which are at leastone of polyatomic or a lone halogen. Such alternate embodiment isindependent of whether the first precursor includes multi-compositionligands, with FIG. 5 showing the first precursor to comprise only onecomposition ligand. Like numerals from the first-described embodimentare utilized where appropriate, with differences being indicated withdifferent letters or with the suffix “a” for substrate 10 a. In FIG. 5,the outermost surface 14 of the substrate has been contacted with afirst precursor M₁E_(q) to chemisorb a first species M₁E_(t) ontooutermost surface 14 of substrate 10 a. By way of example, ligand E andsuffix “q” may be as described above in the FIGS. 1-4 embodiment.

Referring to FIG. 6, outermost surface 14 has been contacted with asecond precursor M₂A_(j)D_(m) to chemisorb a second species M₂D_(u) ontooutermost surface 14. M₂D_(u) is different from first species M₁E_(t).The second precursor comprises a central atom and at least two differentcomposition ligands which are at least one of polyatomic or a lonehalogen, and with the central atoms of the first and second precursorsbeing different. Example properties and attributes of the secondprecursor, including ligands A and D, and suffixes “j”, “m”, and “u”,may be the same as those described above with respect to the firstprecursor in the first embodiment.

Referring to FIG. 7, the chemisorbed first species (not shown) and thechemisorbed second species (not shown) have been contacted with areactant R which reacts with the first species and with the secondspecies to form a reaction product 15 and a new outermost surface 16 ofsubstrate 10 a. By way of example, R may be the same as that describedabove in the FIGS. 1-4 embodiments. Likewise, the reaction product maybe the same or different as that of FIG. 4. Further, the FIGS. 5-7iteration may be repeated one or more times whereby new outermostreaction product surfaces are created to ultimately achieve a suitabledesired thickness of material over substrate material 12. Additionallyand/or alternately, another precursor having the same or differentcentral atom with respect to the first and second precursors could beused immediately before or after exposure to the reactant. Regardless,other processing may occur before or after any of the first, second, andthird parts of the above iteration. Further, the reaction product ofdifferent iterations may be different depending on precursors which areused.

An embodiment of the invention encompasses a method of forming amaterial over a substrate comprising performing at least one iterationof the following temporally separated ALD-type sequence. First, anoutermost surface of a substrate is contacted with a first precursor tochemisorb a first species onto the outermost surface from the firstprecursor. Second, the outermost surface is contacted with a secondprecursor to chemisorb a second species different from the first speciesonto the outermost surface from the second precursor. The first andsecond precursors comprise ligands and have different central atoms. Atleast one of the first and second precursors comprises at least twodifferent composition ligands which are at least one of polyatomic or alone halogen. Third, the chemisorbed first species and the chemisorbedsecond species are contacted with a reactant which reacts with the firstspecies and with the second species to form a reaction product outermostsurface of the substrate. Each of the example FIGS. 1-4 and the FIGS.5-7 embodiments are an example such method.

In one embodiment, only one of the first and second precursors comprisesat least two different composition ligands.

In one embodiment, the deposited material comprises Zr_(x)Al_(y)O_(z),one of the first or second precursors istri(dimethylamino)cyclopentadienyl-zirconium, the other of the first andsecond precursors is trimethylaluminum, and the reactant comprisesoxygen. In one example of such embodiment where the one precursor maycomprise the first precursor, x is greater than y. In another example ofsuch embodiment where the one precursor may comprise the secondprecursor, y is greater than x.

As a specific example, a plurality of silicon substrates having a 10 to12 Angstroms thick outer layer of native oxide was loaded into afurnace. Chamber temperature during processing was 275° C., and chamberpressure was between 0.1 Torr and 0.2 Torr during gas flow to thechamber. Forty iterations were repeated of a first precursor pulse, thenpump down, then inert N₂ flow, then second precursor pulse, then pumpdown, then inert N₂ flow, then reactant pulse, then pump down, and thenN₂ flow. Where the first precursor wastri(dimethylamino)cyclopentadienyl-zirconium, the second precursor wastrimethylaluminum, and the reactant was O₃, the ratio of zirconium oxideto aluminum oxide was about 4:1 and the thickness was 59 Angstromsinclusive of the native oxide. Where the first precursor wastrimethylaluminum, the second precursor wastri(dimethylamino)cyclopentadienyl-zirconium, and the reactant was O₃,the ratio of aluminum oxide to zirconium oxide was about 6.5:1 and thethickness was 58 Angstroms inclusive of the native oxide.

As another example where the material comprises Zr_(x)Si_(y)O_(z), oneof the first or second precursors istri(dimethylamino)cyclopentadienyl-zirconium, the other of the first andsecond precursors is tri(dimethylamino)silane, and the reactantcomprises oxygen. In one example of such embodiment where the oneprecursor may comprise the first precursor, x is greater than y. Inanother example of such embodiment where the one precursor may comprisethe second precursor, y is greater than x.

As a specific example, a plurality of silicon substrates having a 10 to12 Angstroms thick outer layer of native oxide was loaded into afurnace. Chamber temperature during processing was 275° C., and chamberpressure was between 0.1 Torr and 0.2 Torr during gas flow to thechamber. Forty iterations were repeated of a first precursor pulse, thenpump down, then inert N₂ flow, then second precursor pulse, then pumpdown, then inert N₂ flow, then reactant pulse, then pump down, and thenN₂ flow. Where the first precursor wastri(dimethylamino)cyclopentadienyl-zirconium, the second precursor wastri(dimethylamino)silane, and the reactant was O₃, the ratio ofzirconium oxide to silicon oxide was about 16:1 and the thickness was 59Angstroms inclusive of the native oxide. Where the first precursor wastri(dimethylamino)silane, the second precursor wastri(dimethylamino)cyclopentadienyl-zirconium, and the reactant was O₃,the ratio of silicon oxide to zirconium oxide was about 3:1 and thethickness was 56 Angstroms inclusive of the native oxide.

As another example embodiment, both the first and second precursors maycomprise at least two different composition ligands which are at leastone of polyatomic or a lone halogen. Such is shown by way of example inFIGS. 8-10 with respect to a substrate 10 b. Like numerals and lettershave been used from the above-described embodiment, with differencesbeing indicated with different letters or with the suffix “b” forsubstrate 10 b. First, and referring to FIG. 8, outermost surface 14 ofsubstrate 10 b has been contacted with a first precursor M₁A_(j)D_(m) tochemisorb a first species M₁D_(u) onto outermost surface 14 from thefirst precursor. The first precursor comprises a central atom M₁ and atleast two different composition ligands A and D which are at least oneof polyatomic or a lone halogen. Examples for M₁A_(j)D_(m) are asdescribed above.

Second, and referring to FIG. 9, outermost surface 14 has been contactedwith a second precursor M₂G_(c)J_(q) to chemisorb a second speciesM₂G_(r) different from first species M₁Du onto outermost surface 14 fromthe second precursor. The second precursor comprises a central atom M₂which is different from the central atom of the first precursor, and atleast two different composition ligands which are at least one ofpolyatomic or a lone halogen. In FIG. 9, such ligands are represented as“G” and “J” of quantity “c” and “q”, respectively. Example ligands G andJ are the same as any of those described in the above embodiments for A,D, and E. Suffixes “c” and “q” are greater than zero, may or may not bethe same, and may or may not be integers. Additional composition ligandsmay be included as long as at least two are at least one of polyatomicor a lone halogen.

Third, and referring to FIG. 10, the chemisorbed first species (notshown) and the chemisorbed second species (not shown) have beencontacted with a reactant R which reacts with the first species and withthe second species to form a reaction product 15 and a new outermostsurface 16 of substrate 10 b. R may be the same as that described withrespect to the above embodiments. Likewise, the reaction product may bethe same or different as that of the above embodiments. Further, theiteration may be repeated one or more times whereby new outermostreaction product surfaces are created to ultimately achieve a suitabledesired thickness of material over substrate material 12. Additionallyand/or alternately, another precursor having the same or differentcentral atom with respect to the first and second precursors could beused immediately before or after exposure to the reactant. Regardless,other processing may occur before or after any of the first, second, andthird parts of the above iteration. Further, the reaction product ofdifferent iterations may be different depending on precursors which areused.

Embodiments of the invention may be used for achieving or tuning thephysical structure of a deposited film, for example impactingcrystallinity where crystalline material is being deposited or impactingresultant film stress. Such may also impact dielectric and leakagecurrent properties of dielectric layers, or sheet resistance of metallayers.

Embodiments of the invention encompass methods of forming a capacitor,for example, as shown and described with respect to a substrate 30 inFIG. 11. Substrate 30 may or may not be a semiconductor substrate, andcomprises substrate material 32 which may or may not be homogenous. Afirst capacitor electrode 34 and a second capacitor electrode 36 havebeen formed over substrate material 32. Any suitable conductive materialmay be used. Electrodes 34 and 36 may or may not be of the samethickness, may or may not be of the same composition, and may or may notbe homogenous. A capacitor dielectric region 40 has been providedbetween first capacitor electrode 34 and second capacitor electrode 36.

Capacitor dielectric 40 may be provided by performing multipleiterations of the following temporally separated ALD-type sequence asdescribed above. First, an outermost surface of the substrate iscontacted with a first precursor to chemisorb a first species onto theoutermost surface from the first precursor. For example and by way ofexample only, such could be conducted over first capacitor electrodematerial 34 prior to any deposition of second capacitor electrodematerial 36.

Second, the outermost surface is contacted with a second precursor tochemisorb a second species different from the first species onto theoutermost surface from the second precursor. The first and secondprecursors comprise ligands and have different central atoms. At leastone of the first and second precursors comprises at least two differentcomposition ligands which are at least one of polyatomic or a lonehalogen.

Third, the chemisorbed first species and the chemisorbed second speciesare contacted with a reactant which reacts with the first species andwith the second species to form a reaction product new outermost surfaceof the substrate. Any of the processing described above with respect tothe FIGS. 1-4, 5-7, and 8-10 embodiments are examples. The materialdeposited by the iteration may or may not be provided in direct physicaltouching contact with one or both of electrodes 34 or 36.

In one embodiment, and independent of the manner by which capacitordielectric 40 is formed, at least one of the first and second capacitorelectrodes is formed by performing multiple iterations of the followingtemporally separated ALD-type sequence as described above. First, anoutermost surface of the substrate is contacted with a first precursorto chemisorb a first species onto the outermost surface from the firstprecursor. Second, the outermost surface is contacted with a secondprecursor to chemisorb a second species different from the first speciesonto the outermost surface from the second precursor. The first andsecond precursors comprise ligands and have different central atoms. Atleast one of the first and second precursors comprises at least twodifferent composition ligands which are at least one of polyatomic or alone halogen. Third, the chemisorbed first species and the chemisorbedsecond species are contacted with a reactant which reacts with the firstspecies and with the second species to form a reaction product newoutermost surface of the substrate. Any of the processing describedabove with respect to the FIGS. 1-4, 5-7, 8-10, and 11 embodiments areexamples.

In compliance with the statute, the subject matter disclosed herein hasbeen described in language more or less specific as to structural andmethodical features. It is to be understood, however, that the claimsare not limited to the specific features shown and described, since themeans herein disclosed comprise example embodiments. The claims are thusto be afforded full scope as literally worded, and to be appropriatelyinterpreted in accordance with the doctrine of equivalents.

The invention claimed is:
 1. A method of forming a material over a substrate comprising performing at least one iteration of the following temporally separated ALD sequence: contacting an outermost surface of the substrate with a first precursor to chemisorb a first species onto the outermost surface from the first precursor, the first precursor comprising a central atom and at least two different composition ligands, the two different composition ligands being polyatomic or a lone halogen; contacting the outermost surface with a second precursor to chemisorb a second species different from the first species onto the outermost surface from the second precursor, the second precursor comprising a central atom and ligands, the central atoms of the first and second precursors being different, quantity of the chemisorbed second species being less than quantity of the chemisorbed first species; and contacting the chemisorbed first species and the chemisorbed second species with a reactant which reacts with the first species and with the second species to form a reaction product new outermost surface of the substrate.
 2. The method of claim 1 wherein all of the ligands of the second precursor are of the same composition.
 3. The method of claim 1 wherein all of the ligands of the first precursor are of only two different compositions.
 4. The method of claim 3 wherein the first species is void of one of the two different composition ligands.
 5. The method of claim 3 wherein the first precursor has greater quantity of one of the two different composition ligands than the other of the two different composition ligands.
 6. The method of claim 5 wherein the first species is void of the one ligand.
 7. The method of claim 1 wherein the ligands of the first precursor are of more than two different compositions.
 8. The method of claim 1: wherein one of the ligands in the first precursor is larger than each ligand in the second precursor, the first species comprising the one ligand; using steric hindrance in forming the first species from the first precursor to reduce saturation of the central atom of the first precursor chemisorbed to the outermost surface than would otherwise occur under identical process conditions using a different first precursor not having said one ligand; and the forming of the second species from the second precursor increasing quantity of the central atom of the second precursor chemisorbed to the outermost surface than would otherwise occur when forming the first species under said identical process conditions using a different first precursor not having said one ligand.
 9. The method of claim 8 wherein all of the ligands of the second precursor are of the same composition and are not cyclic.
 10. The method of claim 1 wherein the reactant comprises at least one of oxygen, nitrogen, and silicon and the reaction product comprising at least one of an oxide, a nitride, or a silicide, respectively.
 11. The method of claim 10 wherein the reactant comprises oxygen and the reaction product comprises an oxide.
 12. The method of claim 10 wherein the reactant comprises nitrogen and the reaction product comprises a nitride.
 13. The method of claim 10 wherein the reactant comprises silicon and the reaction product comprises a silicide.
 14. A method of forming a material over a substrate comprising performing at least one iteration of the following temporally separated ALD sequence: contacting an outermost surface of the substrate with a first precursor to chemisorb a first species onto the outermost surface from the first precursor, the first precursor comprising a central atom and at least two different composition ligands, the two different composition ligands being polyatomic or a lone halogen; contacting the outermost surface with a second precursor to chemisorb a second species different from the first species onto the outermost surface from the second precursor, the second precursor comprising a central atom and ligands, the central atoms of the first and second precursors being different, one of the ligands in the first precursor being larger than each ligand in the second precursor; and contacting the chemisorbed first species and the chemisorbed second species with a reactant which reacts with the first species and with the second species to form a reaction product new outermost surface of the substrate, the reactant comprising at least one of oxygen, nitrogen, and silicon and the reaction product comprising at least one of an oxide, a nitride, or a silicide, respectively.
 15. The method of claim 14 wherein each of the ligands of the second precursor is non-cyclic.
 16. The method of claim 14 wherein all of the ligands of the second precursor are of the same composition and are not cyclic.
 17. The method of claim 14 wherein the reactant comprises oxygen and the reaction product comprises an oxide.
 18. The method of claim 14 wherein the reactant comprises nitrogen and the reaction product comprises a nitride.
 19. The method of claim 14 wherein the reactant comprises silicon and the reaction product comprises a silicide.
 20. A method of forming a material over a substrate comprising performing at least one iteration of the following temporally separated ALD sequence: contacting an outermost surface of the substrate with a first precursor to chemisorb a first species onto the outermost surface from the first precursor; contacting the outermost surface with a second precursor to chemisorb a second species different from the first species onto the outermost surface from the second precursor, the first and second precursors each respectively comprising ligands and a central atom, the first and second precursors being of different composition relative one another that is characterized at least in part by at least one of the first and second precursors having at least one ligand that is of different composition from all ligands of the other of the first and second precursors, at least one of the first and second precursors comprising at least two different composition ligands, the two different composition ligands being polyatomic or a lone halogen; and contacting the chemisorbed first species and the chemisorbed second species with a reactant which reacts with the first species and with the second species to form a reaction product new outermost surface of the substrate.
 21. A method of forming a material over a substrate comprising performing at least one iteration of the following temporally separated ALD sequence: contacting an outermost surface of a substrate with a first precursor to chemisorb a first species onto the outermost surface from the first precursor, the first precursor comprising a central atom and ligands; contacting the outermost surface with a second precursor to chemisorb a second species different from the first species onto the outermost surface from the second precursor, the second precursor comprising a central atom and at least two different composition ligands, the two different composition ligands being polyatomic or a lone halogen, the central atoms of the first and second precursors being different, a greater quantity of the second species being deposited onto the outermost surface than quantity of the first species deposited onto the outermost surface; and contacting the chemisorbed first species and the chemisorbed second species with a reactant which reacts with the first species and with the second species to form a reaction product new outermost surface of the substrate. 